How Medical Marijuana Works:
Medical marijuana is composed of natural compounds called cannabinoids that are located in areas of the nervous system that affect movement, coordination, responses to stress, and responses to inflammation and pain. As well, they are widely distributed throughout the gastrointestinal (GI) system. Because of these properties, marijuana is thought to help alleviate anxiety, reduce inflammation, relieve pain, control nausea, relax muscle spasm in multiple sclerosis, and stimulate appetite in patients with cancer and AIDS. Some studies even show that marijuana improved inflammatory bowel symptoms including abdominal pain, nausea, and decreased appetite.
How Cannabis Treats Nausea, Pain and Neuropathy in Cancer Patients:
Cancer patient may benefit from medical marijuana to relieve pain and chemotherapy induced neuropathies as well as to quell nausea/vomiting, increase appetite and calm anxiety. Receptors activated by THC have been studied and proven effective in preventing vomiting following chemotherapy.
Other studies have shown cancer patients taking THC experienced an increase in appetite and slowing of weight loss. Cannabinoids found in marijuana also inhibit the neurons that transmit pain by binding pain receptors found in the peripheral nerves.
More recently, in vitro studies have shown that cannabinoids can slow the growth and /or kill certain types of cancer cells. Animal studies have found that cannabinoids may halt both the growth and spread of certain forms of cancer. While medical marijuana may not replace conventional therapies, cannabinoids may be a useful adjunct or alternative for patients.
How Cannabis Treats Sickle Cell Pain:
Patients with sickle cell disease (SCD) suffer from chronic and debilitating pain. Studies have found that SCD patients using marijuana required less opiate analgesia and that SCD patients may be able to mitigate pain safely using marijuana. Additionally, a recent study in sickle mice found that cannabinoids mitigate mast cell activation, which contribute to neurogenic inflammation and hyperalgesia, via both CB1 and CB2 receptors.
How Cannabis Treats Chronic Pain and Neuropathy:
In clinical trials, participants suffering from chronic pain and neuropathies who used marijuana tended to need less pain medication. Cannabinoids found in marijuana inhibit the neurons that transmit pain by binding pain receptors found in the peripheral nerves.
Cannabinoids have also been found to decrease inflammation and nociceptive pain by inhibiting the production of NF-kb and inflammatory cytokines. The numerous cannabinoids in marijuana contribute synergistically to these pain-relieving properties.
How Cannabis Treats Inflammatory Bowel Disease:
Evidence has shown that cannabinoid receptors may limit intestinal inflammation and decrease intestinal motility. CB1 and CB2 receptors are found in all layers of the intestinal wall and mediate inhibitory pathways by reducing vagal cholinergic tone.
Studies of patients with IBD have reported that marijuana relieved IBD related symptoms such as abdominal pain, cramping, diarrhea and nausea, and improved appetite. The effects have been especially beneficial in those with a history of abdominal surgeries, chronic abdominal pain and/or a low quality of life. One study found 21 of 30 patient with IBD improved significantly after treatment with marijuana, reducing their Harvey Bradshaw index from 14(+/-6.7) to 7(+/-4.7).
How Cannabis Treats Anxiety and PTSD:
Many studies find that cannabis, particularly CBD, alleviates generalized anxiety, social anxiety, performance anxiety, OCD, panic disorder and posttraumatic stress disorder (PTSD). One study found that highCBD/lowTHC cannabis use reduced depression 50% and anxiety 58% in 888 Canadian patients.
Another showed that cannabis reduced treatment-resistant nightmares in PTSD in 72% of studied patients. Cannabis use in individuals with PTSD has been shown to reduce restlessness, irritability, and sleep difficulties as well as regulate emotions, reduce anxiety and improve overall functioning.
How Cannabis Treats Symptoms of Multiple Sclerosis (MS)
Oral extracts have been shown in studies to improve muscle stiffness and reduce spasticity in patients with multiple sclerosis (MS). Additional studies found that both smoked and oral cannabis were significantly more effective at reducing pain than placebo. Evidence suggests that the cannabis may also improved bladder symptoms associated with MS.
How Cannabis Treats Amyotrophic Lateral Sclerosis (ALS)
Amyotrophic Lateral Sclerosis, also known as ALS, is a neurodegenerative disease where damage to the neurons of the brain and spinal cord leads to progressive weakening and waste of muscle tissue. Patients slowly lose the ability to walk, swallow, and speak. The condition is considered terminal. The main cannabinoids in cannabis, THC and CBD, mainly function in the endocannabinoids system which is responsible for regulating brain function, hormone secretion, and the immune system. Because THC prevents nerve cell damage via the CB1 receptor, treatment with medical cannabis maybe neuroprotective in ALS patients.
Moreover, the anti-inflammatory effects of cannabis on the CB2 receptors might slow tissue damage. There are currently ongoing studies looking at using medical cannabis to reduce spasticity and slow progression. One study that has been completed did show that treatment reduced spasticity compared to placebo.
How Cannabis Treats Parkinson’s Disease and Other Neurodegenerative Disorders
Our body naturally make cannabinoids that function via the endocannabinoid system and control sleep, appetite, mood, and inflammation. The CB1 and CB2 receptors of the endocannabinoid system are found in high numbers in the basal ganglia – the area of the brain that controls movement and is affected in Parkinson’s disease. The cannabinoids found naturally in cannabis activate these receptors and may protect brain cells because of their anti-inflammatory effects.
Further, people with Parkinson’s disease have fewer CB1 receptors than people who are not afflicted with the disease. Thus, increasing CB1through cannabis may improve tremors and alleviate dyskinesia. The CB2 receptor has potential to modify disease progression through its neuroprotective properties.
Studies have shown cannabis to improve the quality of life, decrease tremor and slowness, and decrease psychosis and hallucinations. While some results have been positive, the effects of medical marijuana are probably not completely understood, which is why more studies, especially those with more subjects, are needed.
How Cannabis Treats Seizure Disorders
Medical cannabis acts on the CB1 and CB2 receptors of the endocannabinoid system. CB1 receptor activity diminishes the excitability of neuronal cells. Our body naturally increases the expression of CB1 during a seizure.
This increase in CB1is thought to be the mechanism of action for seizure control. THC acts via CB1 receptors; CBD acts synergistically with THC. Together they decrease seizure activity. That said, the majority of studies have found higher CBD:TCH ratios to be more effective.
Medical cannabis as a treatment for seizure is probably the best studied. In fact, one forms of cannabis, Epidiolex, has been approved by the FDA for use in seizure disorder. There have been multiple studies showing that medical cannabis can reduce seizure activity by 40-50% in adults and up to 89% in children. In one study 9% of children became seizure free. While there is still a paucity of literature, the FDA approval of Epidiolex will hopefully allow more research in this area.
How Cannabis Treats Autism
The cannabinoids found in cannabis exert their effects by binding to protein receptors CB1 and CB2 which are found in endocannabinoid system of the body. They can affect neuronal excitability or reduce inflammation. Studies have found the CBD, a main cannabinoid in cannabis, significantly improved anxiety and other behavioral traits in people with Fragile X syndrome, a condition related to autism. It has also been shown to lessen seizures and improved learning in children with CDKL5 deficiency disorder, an autism linked condition. That said, CBD may not be enough.
A 2018 study found CBD and THC together decreased aggressive outburst in autistic children and improved quality of life in teenagers with autism. They found fewer seizures, tics, depression, and outbursts. Still, research is mixed and occasionally inconclusive with some reporting adverse outcomes. Currently, there are large scale trials looking at cannabis and autism and soon we will have more evidence. Until then, the use of cannabis in autism is a decision autism patients and their families must have with their health care provider.